Preform for a container produced by stretch-blow moulding

Abstract

The invention relates to a preform ( 1 ) for making a package by blow-moulding comprising three separate components joined to one another, namely a side wall ( 3 ), a base ( 4 ), and an upper part ( 2 ) comprising an opening, characterized in that the thickness of the side wall ( 3 ) is smaller than the thickness of the base ( 4 ). The invention also relates to a package obtained by blow-moulding said preform ( 1 ).

1 . Preform ( 1 ) for making a package by blow-moulding comprising three separate components joined to one another, namely a side wall ( 3 ), a base ( 4 ), and an upper part ( 2 ) comprising an opening, characterized in that the thickness of the side wall ( 3 ) is smaller than the thickness of the base ( 4 ) and smaller than the thickness of the upper part ( 2 ). 
     
     
         2 . Preform ( 1 ) according to  claim 1 , in which the side wall ( 3 ) is flexible. 
     
     
         3 . Preform ( 1 ) according to  claim 2 , in which the side wall ( 3 ) has a thickness of less than 400 microns. 
     
     
         4 . Preform ( 1 ) according to  claim 2 , in which the side wall ( 3 ) is composed of a laminate. 
     
     
         5 . Preform ( 1 ) according to  claim 2 , in which the side wall ( 3 ) is formed by extrusion. 
     
     
         6 . Preform ( 1 ) according to  claim 1 , in which the base ( 4 ) and the upper part ( 2 ) are injection-moulded or compression-moulded. 
     
     
         7 . Preform ( 1 ) according to  claim 1 , of which at least two components are joined by welding. 
     
     
         8 . Preform ( 1 ) according to  claim 1 , of which at least two components are joined by snap-fastening. 
     
     
         9 . Preform ( 1 ) according to  claim 1 , of which the thickness of the upper part ( 2 ) is two times greater than the thickness of the side wall ( 3 ). 
     
     
         10 . Preform ( 1 ) according to  claim 1 , of which the side wall ( 3 ) is multilayered. 
     
     
         11 . Preform ( 1 ) according to  claim 1 , of which the inside diameter of the opening is less than the inside diameter of the side wall ( 3 ). 
     
     
         12 . Preform ( 1 ) according to  claim 1 , of which the side wall ( 3 ) is cylindrical. 
     
     
         13 . Preform ( 1 ) according to  claim 1 , of which the side wall ( 3 ) has an oval cross section. 
     
     
         14 . Preform ( 1 ) according to  claim 1 , of which the side wall ( 3 ) has a polygonal cross section. 
     
     
         15 . Preform ( 1 ) according to  claim 1 , of which the side wall ( 3 ) comprises a printed design. 
     
     
         16 . Method of blow-moulding a preform ( 1 ) comprising at least three separate components welded to one another, namely a side wall ( 3 ), a base ( 4 ) and an upper part ( 2 ) comprising an opening; method consisting in deforming said preform by blow-moulding in the cavity of a mould; method characterized in that only the side wall ( 3 ) is deformed by blow-moulding, in that the axial stretch ratio of the preform is less than 1.1 and in that the radial stretch ratio of the preform is less than 5. 
     
     
         17 . Method according to  claim 16 , consisting in not deforming the side wall ( 3 ) at the join with the base and the upper part. 
     
     
         18 . Method according to  claim 16 , consisting in blow-moulding said preform ( 1 ) at ambient temperature in the mould cavity. 
     
     
         19 . Method according to  claim 16 , consisting in heating only the side wall ( 3 ) of said preform ( 1 ) before blow-moulding. 
     
     
         20 . Method according to  claim 16 , consisting in axially blocking the base ( 4 ) and the upper part ( 2 ) during the blow-moulding in order to prevent an elongation of said preform ( 1 ). 
     
     
         21 . Package obtained by blow-moulding a preform ( 1 ) according to  claim 1 , characterized in that its side wall ( 3 ) comprises at least two cylindrical parts, a first one being located at the join between the side wall ( 3 ) and the base ( 4 ) and the second one being located at the join between the side wall ( 3 ) and the upper part ( 2 ); in that the diameter of said cylindrical parts is identical; and in that the ratio between the maximum diameter and the diameter at the joins is less than 5.